The invention relates to a mounting device for roof racks on motor vehicles, and more particularly to a mounting device which is secured to longitudinally-extending roof channels.
A mounting device for a roof rack is known from German patent document DE 36 37 856 A1. An elongate base plate is locally mounted to the bottom of a roof channel that extends in the longitudinal direction of the vehicle, said plate being held in place by bolts to the sheet metal parts of the roof. The base plate also comprises an upwardly projecting threaded sleeve at whose top, when the flap is open, a supporting part of a roof rack, not shown in greater detail, can be fastened. The top of the threaded sleeve is aligned approximately horizontally.
In this arrangement, relatively high surface pressures develop in the connecting area of the threaded sleeve/supporting part because of the small cross section of the threaded sleeve, so that this design is suitable only for accepting and conducting relatively small forces and therefore only for small roof loads.
A goal of the invention is to provide a supporting part of a roof rack and a base plate secured to the body that accepts large roof loads and conducts them in a satisfactory manner into the fixed body.
This and other goals have been achieved according to the present invention by providing a mounting device for securing a roof rack on a motor vehicle having a roof channel extending in a longitudinal direction, said mounting device comprising: a base plate to be fastened to a bottom of the roof channel, said base plate defining at least one threaded section for receiving a mounting bolt; a support part which supports the roof rack, said support part having an upright rib with at least one support surface on a lower side thereof, said support surface sloping obliquely to said mounting bolt in a transverse direction of the vehicle, each of said at least one support surfaces engaging a respective corresponding support surface on an upper side of said base plate, said base plate defining at least one longitudinally extending depressed groove adjacent said corresponding support surface, said groove receiving a downwardly projecting guide nose of said support part.
This and other goals have been achieved according to the present invention by providing a mounting device for securing a roof rack on a motor vehicle having a roof channel extending in a longitudinal direction and having a width in a transverse direction, said mounting device comprising: a base plate including a longitudinally extending base portion to be engaged with said roof channel, and a raised portion extending upwardly from said base portion, said raised portion extending longitudinally along a portion of a longitudinal length of said base portion, an upwardly facing support surface of said raised portion being sloped along said transverse direction, said base portion defining a longitudinally extending groove on each longitudinal side of said raised portion; and a support part to be engaged with said roof rack, said support part including a downwardly facing support surface which matingly engages said upwardly facing support surface of the base plate, said support part having a guide nose extending downwardly adjacent each longitudinal end of the downwardly facing support surface that said guide noses are disposed in respective ones of said grooves defined in the base plate.
By designing the main support surface as a sloping plane with respect to the screwing direction, the forces conducted through the bolt can advantageously be divided into a horizontal component and a vertical component relative to the screwing direction. In addition, the sloping plane increases the supporting surface between the supporting part and the base plate, so that a lower surface pressure results. In addition, because of the sloping plane, regardless of manufacturing tolerances and possible wear, a 100% shapewise connection is always obtained. The shapewise connections provided laterally next to the supporting surfaces between the base plate and the supporting part conduct the forces that develop in the X and Y directions into the fixed body in a satisfactory manner, and the load on the screw connection is relieved.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.